JP2730380B2 - Drilling method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piercing method, and more particularly to a piercing method for installing holes such as explosive charging holes, lock bolt holes, anchor bolt holes and the like in the ground.

[0002]

2. Description of the Related Art In the construction of a mountain tunnel or the like, a hole for loading an explosive and a hole for burying a rock bolt are used for blasting. In this type of drilling work, a drill for drilling with a bit attached to the tip of a rod is attached to a rock drill, and rotation and percussion motion are transmitted to the bit to drill the ground by impact drilling. The generated scrap is discharged from between the drill for drilling and the ground around the drill. Conventionally, air and water are injected in parallel with the drilling work,
The drill is cooled, dust is prevented, and debris is discharged, but there are the following problems.

[0003] In other words, when water is used, there are problems such as muddy soil and muddy scaffolding. In addition, the perforation walls of sandstone, horned rock, etc. are blocked by the impact of drilling and flushing water,
The drill was caught by jamming, and the work efficiency was reduced due to the inability to drill such as breakage of the drill. Also, when the air is increased, problems such as cooling and dust have occurred. In addition, the roughening of the perforated wall impairs the work of loading explosives, the blasting effect, and the fixing of rock bolts.

[0004] Therefore, it has been studied to use air bubbles for the purpose of preventing dust from being generated and preventing muddying and, at the same time, making the perforated wall self-supporting.
No. 4, JP-A-2-232496 (international classification:
In E21C 7/06) and the like, a method and an apparatus are disclosed in which air bubbles are jetted from the tip of a bit, and a hole called a chip is made into a slurry while slurry is formed.

[0005]

However, in such a conventional method of using air bubbles, a foaming agent such as a surfactant for forming air bubbles by compressed air is separately required, and the geology of the ground to be perforated and cutting are required. Due to the particle size distribution of the shear, the presence of groundwater, etc., the expansion ratio of the air bubbles becomes too large, so adjust the amount of the thickener added and the volume ratio of the air to maintain the proper fluidity and compressibility of the shear. There was a problem that it was not easy to correct the expansion ratio.

Further, when the drilling length becomes long, the pressure at the time of shear discharge becomes too large, and due to the compressibility of bubbles having an excessive foaming rate, soil particles come into contact with each other and the internal friction angle becomes too large. There has been a problem that a phenomenon in which sediment accumulates in the vicinity, and it becomes difficult to discharge the shear.

Accordingly, the present invention has been made to solve the above-mentioned problems, and it is possible to mix air bubbles into the cutting waste without using a foaming agent, and to reduce the foaming ratio of the air bubbles to thereby reduce the cutting efficiency. It is an object of the present invention to provide a drilling method capable of maintaining appropriate compressibility, fluidity, and the like of shear.

[0008]

Means for Solving the Problems In order to achieve the above object, the drilling method of the present invention is to feed a water-soluble polymer solution to a drill with a compressed air and to remove these from near the tip of the drill. By jetting the water-soluble polymer solution, the water-soluble polymer solution is formed into bubbles, which are mixed with the cut soil between the drill and the outer peripheral ground to form the holes.

Here, the vicinity of the tip of the drill is a concept that covers not only the ejection port provided on the outer periphery but also the opening provided inside the drill.

The water-soluble polymer is, for example, a water-soluble cellulose ether which exhibits a viscosity when dissolved in water, and preferably uses methylcellulose, hydroxyethylcellulose, carboxymethylcellulose or the like.

Further, in the drilling method of the present invention, the concentration of the water-soluble polymer in the water-soluble polymer solution may be 0.1 to 0.1.
By changing it in the range of 0.8% by weight, it is possible to perform drilling while controlling the expansion ratio in accordance with the geology of the ground to be drilled.

Here, if the concentration of the water-soluble polymer is less than 0.1% by weight, the viscosity is low and it is not possible to form a bubble. Both are not preferred because they cannot be performed.

Further, in the perforation method of the present invention, a superabsorbent resin which becomes like a sherbet or grease when dissolved in water may be mixed into the water-soluble polymer solution.

[0014]

In the drilling method according to the present invention, the water-soluble polymer solution is fed to the drill with the compressed air to form bubbles, which are mixed into the cutting soil between the drill and the outer ground. The water-soluble polymer dissolves in water and exhibits a viscous property. This liquid is relatively resistant to metal ions in the soil, so that it is difficult to decompose, and has a foaming function such that it easily foams by stirring with a mixer. The foaming ratio of bubbles formed by the foaming agent is generally lower than that of bubbles generated by the foaming agent. However, since the foaming agent has high viscosity and tackiness, it is hardly lost to a soft rock mass having many cracks, and the surrounding ground is not disturbed. Further, even if water is absorbed by the compacted viscous soil and defoaming occurs, since the water-soluble polymer itself remains viscous, the function of improving the fluidity of the cut soil can be left as a perforated material. Furthermore, if a nonionic polymer is used as the water-soluble polymer, a chemically stable perforated material is formed even in a flooded clay with a large basic capacity.

In the perforation method according to the present invention, since the water-soluble polymer solution itself becomes foamed by the action of compressed air, the foaming ratio can be easily adjusted by adjusting the concentration within a predetermined range. Is adjustable.

Further, when the perforation length is increased, it can be easily dealt with by increasing the concentration of the water-soluble polymer, lowering the expansion ratio, and suppressing the compressibility.

Further, when the superabsorbent resin is mixed with the water-soluble polymer solution, a state in which a gel of the superabsorbent resin is mixed with the viscous water-soluble polymer solution, or a colloid in which fine air is further dispersed. States are formed, which mutually prevent the tendency to separate due to external forces such as weight. That is, for example, when the above three are used, the sedimentation of the gel and the floating of the air particles are balanced in the viscous liquid, a relatively stable colloid system is maintained, and the separation of the viscous liquid is performed in a grease-like manner. The gel that has entered is blocked, and the gel is also protected from deterioration due to metal ions in the soil and mechanical friction by viscous liquids and compressive air particles. Therefore, it can be expected that these effects are mixed in the earth and sand, so that the fluidity of the cut earth and sand in the perforations is improved.

[0018]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

The drilling method according to the present embodiment is intended for, for example, dirt clay or soft bedrock in which the size of the cut is 20% or less in fines due to cutting soil. As shown in FIG. 1, the drilling apparatus 20 used in the drilling method according to the present invention connects a plurality of relay rods 5 via a joint 4 to a shank rod 3 connected to the rock drill 1 to form a state-of-the-art relay. The bit 6 is screwed and fixed to the tip of the rod 5. Further, the rock drilling machine 1 includes a motor 7 for rotationally driving the shank rod 3 and a striking device 8 facing the rear end of the shank rod 3, and transmits rotation and percussion motion to the drill 2 for drilling.

At the center of the shank rod 3 and the relay rods 5, flow holes 3a, 5a are formed, and a swivel joint 9 is arranged on the outer periphery of the shank rod 3. This swivel joint 9 has
The hose 10 is connected, and a merging device 14 is connected to a base side of the hose 10. And in the merging device 14,
An air compressor 11 for supplying compressed air via a flow control device TA; and a water-soluble compressor for storing a methylcellulose solution as a water-soluble polymer solution supplied via a flow control device TB and a pump P. A polymer solution tank 12 is connected thereto, and the flow rate adjusting device TB is supplied via a transfer pump 21 for feeding a gel formed by dissolving the superabsorbent resin in water as needed. The highly absorbent resin transfer line 22 is connected. Here, the methylcellulose solution contained in the water-soluble polymer solution tank 12 is a nonionic additive made from pulp and having a concentration of 0.1 to 0.8% by weight.

Then, the methylcellulose solution converted into the gas-liquid two-phase fluid by the merger 14 and the compressed air are connected to the hose 1.
0 and the swivel joint 9, and each rod 3,5
The methylcellulose solution is supplied to the bit 6 attached to the tip of the drill 2 through the flow holes 3a and 5a formed in the drilling hole 2 in a state where the solution tends to form bubbles. Bit 6 is
As shown in FIG. 2, a tapered drilling tool 6
a provided integrally, and the inside thereof is provided with the flow hole 5.
a, a plurality of spouts 6b having the same diameter which are continuous straight and a plurality of spouts 6c branching obliquely outward of the cutting tool 6a are formed from the spout 6b. A groove 6d is formed.

In the above configuration, as shown in FIG.
When the gas-liquid two-phase fluid is ejected from the ejection port 6c, the ejected fluid passes through the hole wall of the perforation E1 and the gap between the soil particle groups E2 in which the shears are randomly arranged, and travels through the inside of the groove portion 6d to produce the ejection pressure. As a result, a sharp resistance is generated in these gaps, and a turbulent state caused by the resistance causes the methylcellulose solution to efficiently become bubbles.

Then, the methylcellulose solution mixed in the cutting soil between the drill 2 for drilling in the drilling and the outer peripheral ground thereof in the foaming state increases the fluidity of the cutting soil and facilitates this. Make it dischargeable. Also, if the expansion ratio is changed by changing the concentration of the methylcellulose solution in the water-soluble polymer solution tank 12, the geology of the perforated ground,
Appropriate fluidity of the cutting waste can be easily maintained in accordance with the particle size distribution of the cutting waste, the presence of groundwater, and the like. When the perforation length becomes long, the foaming ratio is lowered by increasing the concentration of the methylcellulose solution, and the compressibility of the bubbles is suppressed. Further, by mixing a highly absorbent resin into the methylcellulose solution as required, a stable colloidal state is formed by the action of the gel, and the fluidity of the cut soil can be further enhanced.

Further, the cutting earth and sand that has flowed out of the hole is subjected to a solidification treatment by mixing a solidifying agent such as cement, quick lime, etc., and is carried out outside the site.

[0025]

As described above, according to the drilling method of the present invention, the water-soluble polymer solution is fed together with the compressed air to form bubbles, which are cut between the drill and the outer peripheral ground. Since the drilling is performed while being mixed with the earth and sand, the bubbles are generated in the earth and sand without using a foaming agent, whereby the fluidity of the earth and sand can be improved and the earth and sand can be easily discharged out of the hole. In addition, by adjusting the concentration of the water-soluble polymer solution, the foaming ratio can be changed according to the soil properties of the ground to be cut, and the appropriate fluidity of the cutting shear can be easily maintained, and the water-soluble polymer can be easily maintained. By reducing the foaming ratio by increasing the concentration of, it is possible to suppress the compressibility of the bubbles and easily maintain the function of discharging the cut sand even in a long perforated hole. Furthermore, by mixing a highly absorbent resin, the fluidity of the cut soil can be further enhanced by the action of the gel.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing one embodiment of a drilling method according to the present invention.

FIG. 2 is an enlarged sectional view of a bit part of FIG.

FIG. 3 is an enlarged sectional view in a perforated state.

[Explanation of symbols]

 2 Drill for drilling 6 bit 10 Hose 11 Air compressor 12 Water soluble polymer solution tank 14 Combiner 20 Drilling device 22 High absorbent resin transfer line

Claims (3)

(57) [Claims] 1. A water-soluble polymer solution is fed to a drill with a compressed air, and the water-soluble polymer solution is blown out from the vicinity of the tip of the drill to form a bubble in the water-soluble polymer solution. A drilling method characterized in that drilling is performed while being mixed in earth and sand cut between the outer peripheral ground and the ground. 2. The perforation is performed while controlling the expansion ratio by changing the concentration of the water-soluble polymer in the water-soluble polymer solution in the range of 0.1 to 0.8% by weight. The drilling method according to claim 1. 3. The perforation method according to claim 1, wherein a superabsorbent resin is mixed into the water-soluble polymer solution.